Wool-dye and process of making same.



UNITED STATES PATENT OFFICE.-

MYRTIL KAHN, OF ELBERFELD, GERMANY, ASSIGNOR TO FARBENFAB- RIKEN OFELBERFELD 00., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

WOOL-DYE AND PROCESS OF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 722,715, dated March17, 1903.

Application filed October 16, 1902.

To all whom it may concern.-

Be it known that I, MYRTIL KAHN, doctor of philosophy, chemist, residingat Elberfeld, Germany, (assignor to the FARBENFABRIKEN OF ELBERFELD 00.,of New York,) have invented a new and useful Improvement in lVool-Dyeand Process of Making Same; and

I do hereby declare the following to be an exact and clear descriptionof my invention.

My invention relates to the production of a new and valuable azodyestuff by combining the diazo derivative ofortho-amidophenolpara-sulfonic acid having the formula:

with 1 5-di0xynaphthalene.

In carrying out my process practically I can proceed as follows, theparts being by weight: Nineteen parts of ortho-amidophenolpara-sulfonicacid are diazotized in the usual manner, and the resulting diazocompound is stirred into a mixture of sixteen parts of 1:5-dioxynaphthalene with ice-water. Causticsoda lye is added until themixture is alkaline. The dioxynaphthalene entersinto solution and theformation of the dyestufi begins. After being stirred for some time theexcess of caustic-soda lye is neutralized by means of hydrochloric acid,and the new dyestufi is precipitated by the addition of common salt,filtered off, and dried. The new coloring-matter thus obtained is, whendry and pulverized, a dark-brown powder soluble in water to a violetsolution, turning blue on the addition of a small quantity ofcaustic-soda lye, which color is changed to violet on adding a largerquantity of caustic-soda lye. It is soluble in concentrated sulfuricacid of 66 Baum, with a violet-black color, turning violet by theaddition of ice, a dark precipitate being obtained. It dyes wool fromacid-bath violet- By subsequently treating the red shades.

Serial No.127,602. (Specimens) dyed fiber with chromium compounds react-I ing as oxidizing agentssuch as chromates, bichromates, or the liketheshades are changed to deep black, distinguished for great fastness, tothe potting process, which is a finishing process for woolen piecegoods. In this process the goods are entered into boiling water andallowed to remain there until the water is cold. The goods thus assume ahigh degree of gloss and softness, and, according to the effect desired,the potting may be repeated several times. They also resist milling andwashing and possess a good fastness against the action of light.

Having now described my invention, what I claim is- 1. The hereindescribed process for the manufacture of a new azo dyestuff for wool,which consists in first combining the diazo compound of orthoamidophenolpara sulfonic acid having the above-given formula with1:5-dioxynaphthalene and secondly isolating the monoazo dyestuif thusproduced, substantially as hereinbefore described.

2. The herein-described new azo dyestuff derived from ortho-amidophenol-para-sulto deep black by a subsequent treatment with chromium compoundsreacting as oxidizing agents, substantially as described.

In testimony whereof I have signed my name in the presence of twosubscribing witnesses.

MYRTIL KAHN.

Witnesses:

.O'rro KoNIG,

J. A. RITTERSHAUS.

